A 1½-year-old boy was run over and killed in the driveway of an in-home day care Thursday afternoon.Thornton police said they found the boy suffering from severe head trauma in the driveway at 9221 Jackson St. at 4:42 p.m. The child, identified as Riley Lawyer, was pronounced dead at a local hospital.The owner of the day care, 34-year-old Robyn Miller, was backing out of her driveway when she struck the child, said Thornton police spokesman Matt Barnes.Miller was going to pick up some other kids and she thought she had loaded all the children into the vehicle, but obviously missed Riley, Barnes said.As she was backing out, she knew she ran over something but she did not know what she hit, police said. When she got out she found Riley underneath the vehicle."She drove physically over the child. The child was not pinned," Barnes said.Police said drugs or alcohol are not suspected in the accident.Miller is "devastated," Barnes said.The boy's mother was driving from work, on her way to pick up her son, when the accident happened, his family members said.The child's death is under investigation by the traffic unit of the Thornton Police Department.A check with the Colorado Department of Human Services showed that the day care was licensed in February 2002 and has no history of complaints. It is licensed to care for up to six children from newborn to 13 years old. It was last inspected on March 9 and there were no red flags.